The Figure Below Illustrates the Rain Shadow Effect

The figure below illustrates the rain shadow effect.
What best explains why the leeward side of the mountain experiences less rainfall?

A) The air mass simply has no more moisture; it was all released on the windward slope.
B) As the air flows downslope it is compressed and warmed, allowing it not only to retain its own moisture but often removing moisture from the soil beneath as well.
C) The rotation of the Earth causes the air moving downslope to be displaced to the right, reducing rainfall behind the mountain.
D) All of the above contribute to the rain shadow effect.